(i) Technical Field
The present invention relates to an image forming apparatus and an image forming method.
(ii) Related Art
An image forming apparatus using an electrophotographic method forms an image by utilizing a toner which is a coloring material on an image carrier such as a photosensitive drum or an intermediate belt and transfers the toner image thus formed onto a recording medium such as a printing paper, thereby forming an image on the recording medium.
An image portion corresponding to the toner image formed by the coloring material and a non-image portion in which a ground (a ground color) of the recording medium appears unchanged are present together in an image forming region on the image carrier. It has been known that a so-called “toner fog” might be generated, that is, a slight amount of the toner which is the coloring material might become attached to the non-image portion though it is not put thereon intentionally.
However, a processing for controlling the fog preventing potential is complicated. In particular, it is supposed that a perfect control is almost impossible when the configuration of the image and non-image portions is detailed. Furthermore, occurrence of secondary problems such as an image defect might also be increased.